<?php
/*
 *  $Id$
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This software consists of voluntary contributions made by many individuals
 * and is licensed under the LGPL. For more information, see
 * <http://www.doctrine-project.org>.
 */

namespace Doctrine\Common\Cache;

/**
 * Interface for cache drivers.
 *
 * @license http://www.opensource.org/licenses/lgpl-license.php LGPL
 * @link    www.doctrine-project.org
 * @since   2.0
 * @version $Revision: 3938 $
 * @author  Benjamin Eberlei <kontakt@beberlei.de>
 * @author  Guilherme Blanco <guilhermeblanco@hotmail.com>
 * @author  Jonathan Wage <jonwage@gmail.com>
 * @author  Roman Borschel <roman@code-factory.org>
 */
interface Cache {
	/**
	 * Fetches an entry from the cache.
	 * 
	 * @param string $id cache id The id of the cache entry to fetch.
	 * @return string The cached data or FALSE, if no cache entry exists for the given id.
	 */
	function fetch($id);
	
	/**
	 * Test if an entry exists in the cache.
	 *
	 * @param string $id cache id The cache id of the entry to check for.
	 * @return boolean TRUE if a cache entry exists for the given cache id, FALSE otherwise.
	 */
	function contains($id);
	
	/**
	 * Puts data into the cache.
	 *
	 * @param string $id The cache id.
	 * @param string $data The cache entry/data.
	 * @param int $lifeTime The lifetime. If != 0, sets a specific lifetime for this cache entry (0 => infinite lifeTime).
	 * @return boolean TRUE if the entry was successfully stored in the cache, FALSE otherwise.
	 */
	function save($id, $data, $lifeTime = 0);
	
	/**
	 * Deletes a cache entry.
	 * 
	 * @param string $id cache id
	 * @return boolean TRUE if the cache entry was successfully deleted, FALSE otherwise.
	 */
	function delete($id);
}